1. Field of the Invention
The present invention relates to the field of data processing. More specifically, embodiments of the present invention relate to data synchronization and/or accessing systems utilizing a server and one or more electronic devices.
2. Related Art
As the components required to build a computer system have reduced in size, new categories of portable electronic devices and computer systems have emerged. One of the new categories of computer systems is the “palmtop” computer system. A palmtop computer system is a computer that is small enough to be held in the hand of a user and can therefore be “palm-sized.” Most palmtop computer systems are used to implement various Personal Information Management (PIM) applications such as an address book, a daily organizer (calendar, datebook, etc.) and electronic notepads, to name a few. Palmtop computers with PIM software have been know as Personal Digital Assistants (PDAs). Many PDAs have a small and flat display screen associated therewith. Moreover, PDAs and cell phones are being integrated together resulting in a single intelligent device that provides wireless communication capability.
User convenience and device value are very important factors for portable electronic devices and systems that may include portable electronic devices. Typically, portable electronic devices are employed while the user is on the run, e.g., in business meetings, on business travel, personal travel, in a vehicle, on foot, etc. Because the user may be occupied or busy while using the portable electronic device, the number of user steps or user tasks required in order to access information from an electronic device (or to store information into the electronic device) is crucial for producing a commercially successful and useful product. That is, the more difficult it is to access data from an electronic device, the less likely the user will perform those tasks to obtain the information. Likewise, the easier information is to obtain, the more likely the portable electronic device will be used to obtain that information and the more likely the portable electronic device will become a part of the user's everyday activities. Similarly, the more useful the device, the more the device will be used and acquired.
The rapid penetration of portable electronic devices into the home and business markets has augmented, not replaced, the usefulness of desktop, laptop and server computer systems. As a result, it is not uncommon for a single user to have a portable electronic device and, in addition, also have one or more other computer systems. However, database information needs to be shared between these computer systems. Typically, what is desired is that any of the computer systems be able to make updates and revisions to the database.
FIG. 1A illustrates a three-way synchronization system 26 of the prior art allowing a database to be shared over three devices. System 26 includes a laptop or desktop computer 10, a portable computer system 12 and a web based server 14. Each of the three devices may contain a portion of a common database and each device may allow the user to edit records of its locally resident database copy. Synchronization processes 16, 18 and 20 synchronize the data between any two devices when they become connected together. Synchronization is the process of updating the records of the database from each device, and resolving conflicts, so that each device may have the most updated version of the database as is possible.
One problem with the three-way synchronization system 26 of FIG. 1A is that it often requires complex synchronization software to account for the various conflict resolution mechanisms that are required when any of the three devices may independently update records of the database. Moreover, the client software 22 must be present in each device in order to perform synchronization. By requiring each device to have its own client software, that means new devices that do not have the software are unable to participate in the synchronization. Further, this requirement also makes software revisions more difficult to perform because the client software is distributed on each device.
Another problem with the three-way synchronization system 26 of FIG. 1A is that it often requires complex metadata (including timestamps and revision flags) in order to keep track of the records and the way in which they were updated by the various devices and also the time that they were updated. Because complex metadata is required, standard database structures are not used in system 26. Three-way synchronization also can lead to “slow synchronizations.” Slow synchronization results when a synchronization is performed between device A and device B that erases the revision flags of device A. Then, device A synchronizes with device C which leads to a slow synchronization because the revision flags of device A are gone. This happens frequently when a PDA is synchronized at work and then taken home and synchronized there also. Another problem with the three-way synchronization system 26 is that there is no central location of the database information since it is spread over the devices. This makes it difficult to 1) perform enterprise management tasks, 2) secure the data and 3) back up the data effectively.
FIG. 1B illustrates an n-way synchronization system 36 of the prior art for sharing a database. In this system, the clients 32a-32d each synchronize with a central server 30 but not with each other. Central server 30 resolves synchronization conflicts. Like the system of FIG. 1A, system 36 still requires that each client 32a-32d have its own client software 34 to perform the synchronization. As discussed above, by requiring each client to have its own software, that means new devices that do not have the client software are unable to participate in the synchronization. Further, this requirement also makes software revisions more difficult to perform because each client needs to be separately updated.